J.J. Abrams literally broke his back helping injured Harrison Ford on the new 'Star Wars' set

Hulu/Comedy Central J.J. Abrams was on "The Daily Show" Thursday night promoting his new film "Mission: Impossible - Rogue Nation" (which he produced), but all Jon Stewart wanted to do was get any info about Abrams' next directing effort, "Star Wars: Episode VII - The Force Awakens."

Stewart wasn't successful, but Abrams was willing to open up about the on-set injury Harrison Ford suffered.

"There was a hydraulic door that went down, he was pushed down, and his ankle went 90 degrees," Abrams told Stewart.

The actor broke his ankle, and Abrams described to Stewart how he rushed to Ford's aid.

"I'm trying to lift him up, because that's the kind of guy I am," he said. "I'm trying to lift this door and I hear a pop [in my back] and I go, 'Oh, that's weird.' So I go to the doctor a couple of days alter and he goes, 'Oh, you have a broken back.'"

The doctor informed Abrams that he had broken his L4 in his spine. But the director continued working on "Star Wars."

"A few months later I'm still wearing this really silly back brace under my shirt, nobody knows, I didn't tell anybody. Harrison Ford from across the stage sprints to me faster than I will ever run, and he's like 'Hey, J.J.!'"